In the field of composite elastic materials, there has been a continuing need for composite materials having a high degree of flexibility and elasticity and which may be manufactured at a low cost. In particular, there is a need for a composite elastic material having low stress relaxation, low hysteresis and high recoverable energy. This need has persisted in spite of the fact that such materials could readily be utilized to manufacture a wide variety of garments of both the disposable type, such as disposable diapers, or the durable type, such as pants, dresses, blouses and sporting wear, for example, sweatsuits. Further, such materials could also be utilized in, for example, upholstery, drapery, liner and insulation applications. The characteristics of low stress relaxation, low hysteresis and high recoverable energy are particularly desirable for materials used in these areas because articles manufactured from such materials may be easily put on the body of the wearer or any item, such as a fixed frame, around which the materials may be wrapped. Those characteristics are also very useful because articles manufactured from such materials are able to closely conform to the body of a wearer or any item and repeatedly extend and retract without sagging.
Elastomeric block copolymers blended with large amounts of a polyolefin and/or hydrocarbon resin may, in certain situations, have poor stress relaxation properties and stress-strain tests of such materials show significant hysteresis. Moreover, elastic films or webs with the desired elastic properties may have those properties diminished when processed into a composite elastic material. For example, thermal bonding techniques used to join the elastic materials to the other materials of the composite or additives to the formulation of the elastic films or webs such as, for example tackifying resins which are utilized to enhance the bonding between the elastic materials and the other materials of the composite may have an adverse affect on the elastomeric properties of the elastic composite.
Thus, a void exists with respect to composite elastic materials which have the characteristics of low stress relaxation, low hysteresis and high recoverable energy.